diff --git a/arch/mips/pci/pci-xlr.c b/arch/mips/pci/pci-xlr.c
index 87404d0..3d701a9 100644
--- a/arch/mips/pci/pci-xlr.c
+++ b/arch/mips/pci/pci-xlr.c
@@ -45,6 +45,8 @@
 #include <asm/io.h>
 
 #include <asm/netlogic/interrupt.h>
+#include <asm/netlogic/haldefs.h>
+
 #include <asm/netlogic/xlr/msidef.h>
 #include <asm/netlogic/xlr/iomap.h>
 #include <asm/netlogic/xlr/pic.h>
@@ -226,6 +228,56 @@
 }
 #endif
 
+/* Extra ACK needed for XLR on chip PCI controller */
+static void xlr_pci_ack(struct irq_data *d)
+{
+	uint64_t pcibase = nlm_mmio_base(NETLOGIC_IO_PCIX_OFFSET);
+
+	nlm_read_reg(pcibase, (0x140 >> 2));
+}
+
+/* Extra ACK needed for XLS on chip PCIe controller */
+static void xls_pcie_ack(struct irq_data *d)
+{
+	uint64_t pciebase_le = nlm_mmio_base(NETLOGIC_IO_PCIE_1_OFFSET);
+
+	switch (d->irq) {
+	case PIC_PCIE_LINK0_IRQ:
+		nlm_write_reg(pciebase_le, (0x90 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_LINK1_IRQ:
+		nlm_write_reg(pciebase_le, (0x94 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_LINK2_IRQ:
+		nlm_write_reg(pciebase_le, (0x190 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_LINK3_IRQ:
+		nlm_write_reg(pciebase_le, (0x194 >> 2), 0xffffffff);
+		break;
+	}
+}
+
+/* For XLS B silicon, the 3,4 PCI interrupts are different */
+static void xls_pcie_ack_b(struct irq_data *d)
+{
+	uint64_t pciebase_le = nlm_mmio_base(NETLOGIC_IO_PCIE_1_OFFSET);
+
+	switch (d->irq) {
+	case PIC_PCIE_LINK0_IRQ:
+		nlm_write_reg(pciebase_le, (0x90 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_LINK1_IRQ:
+		nlm_write_reg(pciebase_le, (0x94 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_XLSB0_LINK2_IRQ:
+		nlm_write_reg(pciebase_le, (0x190 >> 2), 0xffffffff);
+		break;
+	case PIC_PCIE_XLSB0_LINK3_IRQ:
+		nlm_write_reg(pciebase_le, (0x194 >> 2), 0xffffffff);
+		break;
+	}
+}
+
 int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 {
 	return get_irq_vector(dev);
@@ -253,6 +305,31 @@
 	pr_info("Registering XLR/XLS PCIX/PCIE Controller.\n");
 	register_pci_controller(&nlm_pci_controller);
 
+	/*
+	 * For PCI interrupts, we need to ack the PCI controller too, overload
+	 * irq handler data to do this
+	 */
+	if (nlm_chip_is_xls()) {
+		if (nlm_chip_is_xls_b()) {
+			irq_set_handler_data(PIC_PCIE_LINK0_IRQ,
+							xls_pcie_ack_b);
+			irq_set_handler_data(PIC_PCIE_LINK1_IRQ,
+							xls_pcie_ack_b);
+			irq_set_handler_data(PIC_PCIE_XLSB0_LINK2_IRQ,
+							xls_pcie_ack_b);
+			irq_set_handler_data(PIC_PCIE_XLSB0_LINK3_IRQ,
+							xls_pcie_ack_b);
+		} else {
+			irq_set_handler_data(PIC_PCIE_LINK0_IRQ, xls_pcie_ack);
+			irq_set_handler_data(PIC_PCIE_LINK1_IRQ, xls_pcie_ack);
+			irq_set_handler_data(PIC_PCIE_LINK2_IRQ, xls_pcie_ack);
+			irq_set_handler_data(PIC_PCIE_LINK3_IRQ, xls_pcie_ack);
+		}
+	} else {
+		/* XLR PCI controller ACK */
+		irq_set_handler_data(PIC_PCIE_XLSB0_LINK3_IRQ, xlr_pci_ack);
+	}
+
 	return 0;
 }